blob: 19e132f1e3697e3d3d9f0d9a8a325d05a2fe0398 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Copied from strings/stringpiece.cc with modifications
#include "base/strings/string_piece.h"
#include <limits.h>
#include <algorithm>
#include <ostream>
#include "base/logging.h"
#include "base/strings/utf_string_conversions.h"
namespace base {
namespace {
// For each character in characters_wanted, sets the index corresponding
// to the ASCII code of that character to 1 in table. This is used by
// the find_.*_of methods below to tell whether or not a character is in
// the lookup table in constant time.
// The argument `table' must be an array that is large enough to hold all
// the possible values of an unsigned char. Thus it should be be declared
// as follows:
// bool table[UCHAR_MAX + 1]
inline void BuildLookupTable(const StringPiece& characters_wanted,
bool* table) {
const size_t length = characters_wanted.length();
const char* const data = characters_wanted.data();
for (size_t i = 0; i < length; ++i) {
table[static_cast<unsigned char>(data[i])] = true;
}
}
} // namespace
// MSVC doesn't like complex extern templates and DLLs.
#if !defined(COMPILER_MSVC)
template class BasicStringPiece<std::string>;
template class BasicStringPiece<string16>;
#endif
std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
return o;
}
std::ostream& operator<<(std::ostream& o, const StringPiece16& piece) {
return o << UTF16ToUTF8(piece);
}
namespace internal {
template<typename STR>
void CopyToStringT(const BasicStringPiece<STR>& self, STR* target) {
if (self.empty())
target->clear();
else
target->assign(self.data(), self.size());
}
void CopyToString(const StringPiece& self, std::string* target) {
CopyToStringT(self, target);
}
void CopyToString(const StringPiece16& self, string16* target) {
CopyToStringT(self, target);
}
template<typename STR>
void AppendToStringT(const BasicStringPiece<STR>& self, STR* target) {
if (!self.empty())
target->append(self.data(), self.size());
}
void AppendToString(const StringPiece& self, std::string* target) {
AppendToStringT(self, target);
}
void AppendToString(const StringPiece16& self, string16* target) {
AppendToStringT(self, target);
}
template<typename STR>
size_t copyT(const BasicStringPiece<STR>& self,
typename STR::value_type* buf,
size_t n,
size_t pos) {
size_t ret = std::min(self.size() - pos, n);
memcpy(buf, self.data() + pos, ret * sizeof(typename STR::value_type));
return ret;
}
size_t copy(const StringPiece& self, char* buf, size_t n, size_t pos) {
return copyT(self, buf, n, pos);
}
size_t copy(const StringPiece16& self, char16* buf, size_t n, size_t pos) {
return copyT(self, buf, n, pos);
}
template<typename STR>
size_t findT(const BasicStringPiece<STR>& self,
const BasicStringPiece<STR>& s,
size_t pos) {
if (pos > self.size())
return BasicStringPiece<STR>::npos;
typename BasicStringPiece<STR>::const_iterator result =
std::search(self.begin() + pos, self.end(), s.begin(), s.end());
const size_t xpos =
static_cast<size_t>(result - self.begin());
return xpos + s.size() <= self.size() ? xpos : BasicStringPiece<STR>::npos;
}
size_t find(const StringPiece& self, const StringPiece& s, size_t pos) {
return findT(self, s, pos);
}
size_t find(const StringPiece16& self, const StringPiece16& s, size_t pos) {
return findT(self, s, pos);
}
template<typename STR>
size_t findT(const BasicStringPiece<STR>& self,
typename STR::value_type c,
size_t pos) {
if (pos >= self.size())
return BasicStringPiece<STR>::npos;
typename BasicStringPiece<STR>::const_iterator result =
std::find(self.begin() + pos, self.end(), c);
return result != self.end() ?
static_cast<size_t>(result - self.begin()) : BasicStringPiece<STR>::npos;
}
size_t find(const StringPiece& self, char c, size_t pos) {
return findT(self, c, pos);
}
size_t find(const StringPiece16& self, char16 c, size_t pos) {
return findT(self, c, pos);
}
template<typename STR>
size_t rfindT(const BasicStringPiece<STR>& self,
const BasicStringPiece<STR>& s,
size_t pos) {
if (self.size() < s.size())
return BasicStringPiece<STR>::npos;
if (s.empty())
return std::min(self.size(), pos);
typename BasicStringPiece<STR>::const_iterator last =
self.begin() + std::min(self.size() - s.size(), pos) + s.size();
typename BasicStringPiece<STR>::const_iterator result =
std::find_end(self.begin(), last, s.begin(), s.end());
return result != last ?
static_cast<size_t>(result - self.begin()) : BasicStringPiece<STR>::npos;
}
size_t rfind(const StringPiece& self, const StringPiece& s, size_t pos) {
return rfindT(self, s, pos);
}
size_t rfind(const StringPiece16& self, const StringPiece16& s, size_t pos) {
return rfindT(self, s, pos);
}
template<typename STR>
size_t rfindT(const BasicStringPiece<STR>& self,
typename STR::value_type c,
size_t pos) {
if (self.size() == 0)
return BasicStringPiece<STR>::npos;
for (size_t i = std::min(pos, self.size() - 1); ;
--i) {
if (self.data()[i] == c)
return i;
if (i == 0)
break;
}
return BasicStringPiece<STR>::npos;
}
size_t rfind(const StringPiece& self, char c, size_t pos) {
return rfindT(self, c, pos);
}
size_t rfind(const StringPiece16& self, char16 c, size_t pos) {
return rfindT(self, c, pos);
}
// 8-bit version using lookup table.
size_t find_first_of(const StringPiece& self,
const StringPiece& s,
size_t pos) {
if (self.size() == 0 || s.size() == 0)
return StringPiece::npos;
// Avoid the cost of BuildLookupTable() for a single-character search.
if (s.size() == 1)
return find(self, s.data()[0], pos);
bool lookup[UCHAR_MAX + 1] = { false };
BuildLookupTable(s, lookup);
for (size_t i = pos; i < self.size(); ++i) {
if (lookup[static_cast<unsigned char>(self.data()[i])]) {
return i;
}
}
return StringPiece::npos;
}
// 16-bit brute force version.
size_t find_first_of(const StringPiece16& self,
const StringPiece16& s,
size_t pos) {
// Use the faster std::find() if searching for a single character.
StringPiece16::const_iterator found =
s.size() == 1 ? std::find(self.begin() + pos, self.end(), s[0])
: std::find_first_of(self.begin() + pos, self.end(),
s.begin(), s.end());
if (found == self.end())
return StringPiece16::npos;
return found - self.begin();
}
// 8-bit version using lookup table.
size_t find_first_not_of(const StringPiece& self,
const StringPiece& s,
size_t pos) {
if (self.size() == 0)
return StringPiece::npos;
if (s.size() == 0)
return 0;
// Avoid the cost of BuildLookupTable() for a single-character search.
if (s.size() == 1)
return find_first_not_of(self, s.data()[0], pos);
bool lookup[UCHAR_MAX + 1] = { false };
BuildLookupTable(s, lookup);
for (size_t i = pos; i < self.size(); ++i) {
if (!lookup[static_cast<unsigned char>(self.data()[i])]) {
return i;
}
}
return StringPiece::npos;
}
// 16-bit brute-force version.
BASE_EXPORT size_t find_first_not_of(const StringPiece16& self,
const StringPiece16& s,
size_t pos) {
if (self.size() == 0)
return StringPiece16::npos;
for (size_t self_i = pos; self_i < self.size(); ++self_i) {
bool found = false;
for (auto c : s) {
if (self[self_i] == c) {
found = true;
break;
}
}
if (!found)
return self_i;
}
return StringPiece16::npos;
}
template<typename STR>
size_t find_first_not_ofT(const BasicStringPiece<STR>& self,
typename STR::value_type c,
size_t pos) {
if (self.size() == 0)
return BasicStringPiece<STR>::npos;
for (; pos < self.size(); ++pos) {
if (self.data()[pos] != c) {
return pos;
}
}
return BasicStringPiece<STR>::npos;
}
size_t find_first_not_of(const StringPiece& self,
char c,
size_t pos) {
return find_first_not_ofT(self, c, pos);
}
size_t find_first_not_of(const StringPiece16& self,
char16 c,
size_t pos) {
return find_first_not_ofT(self, c, pos);
}
// 8-bit version using lookup table.
size_t find_last_of(const StringPiece& self, const StringPiece& s, size_t pos) {
if (self.size() == 0 || s.size() == 0)
return StringPiece::npos;
// Avoid the cost of BuildLookupTable() for a single-character search.
if (s.size() == 1)
return rfind(self, s.data()[0], pos);
bool lookup[UCHAR_MAX + 1] = { false };
BuildLookupTable(s, lookup);
for (size_t i = std::min(pos, self.size() - 1); ; --i) {
if (lookup[static_cast<unsigned char>(self.data()[i])])
return i;
if (i == 0)
break;
}
return StringPiece::npos;
}
// 16-bit brute-force version.
size_t find_last_of(const StringPiece16& self,
const StringPiece16& s,
size_t pos) {
if (self.size() == 0)
return StringPiece16::npos;
for (size_t self_i = std::min(pos, self.size() - 1); ;
--self_i) {
for (auto c : s) {
if (self.data()[self_i] == c)
return self_i;
}
if (self_i == 0)
break;
}
return StringPiece16::npos;
}
// 8-bit version using lookup table.
size_t find_last_not_of(const StringPiece& self,
const StringPiece& s,
size_t pos) {
if (self.size() == 0)
return StringPiece::npos;
size_t i = std::min(pos, self.size() - 1);
if (s.size() == 0)
return i;
// Avoid the cost of BuildLookupTable() for a single-character search.
if (s.size() == 1)
return find_last_not_of(self, s.data()[0], pos);
bool lookup[UCHAR_MAX + 1] = { false };
BuildLookupTable(s, lookup);
for (; ; --i) {
if (!lookup[static_cast<unsigned char>(self.data()[i])])
return i;
if (i == 0)
break;
}
return StringPiece::npos;
}
// 16-bit brute-force version.
size_t find_last_not_of(const StringPiece16& self,
const StringPiece16& s,
size_t pos) {
if (self.size() == 0)
return StringPiece::npos;
for (size_t self_i = std::min(pos, self.size() - 1); ; --self_i) {
bool found = false;
for (auto c : s) {
if (self.data()[self_i] == c) {
found = true;
break;
}
}
if (!found)
return self_i;
if (self_i == 0)
break;
}
return StringPiece16::npos;
}
template<typename STR>
size_t find_last_not_ofT(const BasicStringPiece<STR>& self,
typename STR::value_type c,
size_t pos) {
if (self.size() == 0)
return BasicStringPiece<STR>::npos;
for (size_t i = std::min(pos, self.size() - 1); ; --i) {
if (self.data()[i] != c)
return i;
if (i == 0)
break;
}
return BasicStringPiece<STR>::npos;
}
size_t find_last_not_of(const StringPiece& self,
char c,
size_t pos) {
return find_last_not_ofT(self, c, pos);
}
size_t find_last_not_of(const StringPiece16& self,
char16 c,
size_t pos) {
return find_last_not_ofT(self, c, pos);
}
template<typename STR>
BasicStringPiece<STR> substrT(const BasicStringPiece<STR>& self,
size_t pos,
size_t n) {
if (pos > self.size()) pos = self.size();
if (n > self.size() - pos) n = self.size() - pos;
return BasicStringPiece<STR>(self.data() + pos, n);
}
StringPiece substr(const StringPiece& self,
size_t pos,
size_t n) {
return substrT(self, pos, n);
}
StringPiece16 substr(const StringPiece16& self,
size_t pos,
size_t n) {
return substrT(self, pos, n);
}
#if DCHECK_IS_ON()
void AssertIteratorsInOrder(std::string::const_iterator begin,
std::string::const_iterator end) {
DCHECK(begin <= end) << "StringPiece iterators swapped or invalid.";
}
void AssertIteratorsInOrder(string16::const_iterator begin,
string16::const_iterator end) {
DCHECK(begin <= end) << "StringPiece iterators swapped or invalid.";
}
#endif
} // namespace internal
} // namespace base